1. Field of the Invention
The invention relates to a finned tube heat exchanger, particularly for the condensation of exhaust streams of large turbine plants by cooling air.
2. Description of the Related Art
The finned tube heat exchanger according to DE-PS 34 19 734 is capable of condensing large quantities of steam. Moreover, it has the advantage that a pressure equalization occurs at any location of the heat exchanger tubes between all areas of the tube cross section. Consequently, the condensation of the exhaust steam ends in the forward tube sections facing the flow direction of the cooling air at exactly the same location as in the tube sections which are at the rear in flow direction of the cooling air. Accordingly, it is not likely that dead zones will be formed. Moreover, relatively large cross sections of the tubes are formed, so that the pressure losses due to the larger hydraulic cross section are significantly reduced.
The fins which project perpendicularly from the surfaces of the heat exchanger tubes are smooth and are constructed without projections.
In contrast to this finned tube heat exchanger, the finned tube heat exchanger according to DE-OS 19 58 909 has stop edges which are integrated in the fins between the heat exchanger tubes. The stop edges are formed by pressing surface portions out of the planes of the fins. Consequently, there are obstacles for the cooling air. The heat transfer is improved as a result of this measure, however, with the disadvantage that the pressure loss is increased by a multiple as a result of the stop edges.